And some of these Dake parts may be good candidates for the lost-PLA method, with their passages.
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Semi-Lost-PLA Casting Method
- Thread starter GreenTwin
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Some of it boils down to convenience; ie: how many retracts and cores you want to use.
All of the old engines were made using cores and greensand.
If they can pull the Soule frame pattern, then there is a way to pull your pattern too.
Again, it depends on how much trouble you want to go to, and how many you want to make.
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For the Speedy Twin frame, they blocked out the bearing supports, and the port faces, and then inserted a core back into the sand mold in these locations.
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That is why I said to keep cost down. cores and multi part flasks cost time and money. I'm sure the foundry who did the originals did not do it for fun and would have gone for a simple vertical split if that would have worked.
I designed that pattern with Graham Corry, 35years of casting engines for his Alyn Foundry company. He also felt it was the way to go and if a vertical part line would have done we would have used it but what does he know, probably cast more engines in a week than you have in your life.
I designed that pattern with Graham Corry, 35years of casting engines for his Alyn Foundry company. He also felt it was the way to go and if a vertical part line would have done we would have used it but what does he know, probably cast more engines in a week than you have in your life.
The cores inside of this part are extensive.
Soule was the absolute master of linseed oil cores.
They used chaps to hold all the passage cores in place during castings, and if you look closely at a full-sized Speedy Twin, you can see some of the chaps that are embedded in the casting.
Soule was the absolute master of linseed oil cores.
They used chaps to hold all the passage cores in place during castings, and if you look closely at a full-sized Speedy Twin, you can see some of the chaps that are embedded in the casting.
Yes, fully understood, for convenience and simplicity, but note that a vertical parting line could have been used, with the bearing support included in the casting; mentioned so that hobby folks reading along know it is possible.
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I am not doubting his talent, but that being said, nobody has a monopoly on creative ideas either, even someone with the stature of Graham Corry.
I don't think is really a good idea to limit yourself only to the confines of what others have previously done.
There is almost always a better way to do things other than "the way things have always been done".
I see that every day in my line of work.
"That is the way it has always been done" often means that they just could not come up with a better way to do it; it does not necessarily mean that there is not a better way to do it.
I agree though to some extent, for multiple castings, one has to go with an efficient method, else there is no profit in it.
Modern materials often allow much better ways to do things now than when they used greensand and linseed oil cores.
Some amazing things can be done now with ease with modern materials.
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Well that statement that they did not know what they were doing is quite disrespectful. Have a read of this with 155yrs of business I would think they knew a hell of a lot more than you.
https://www.cfow.org.uk/picture.php?/5259/category/37
Bit of a bigger setup than a back yard that has only done a handful of castings
https://www.cfow.org.uk/picture.php?/4373/category/37
Absolutely no intention of being disrespectful to anyone with that statement.
I have edited it to say the following: "Somebody did not do their parting line anything like I would have done it".
No need to personalize it.
I think we are all entitled to our opinions, and I stand by mine, but I am as you say just a little nobody on a hobby forum.
I have never pretended to be a big foundry, so no need to throw that out.
Call off the attack dogs.
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And again, you should not limit yourself to only the methods others have used for 155 years.
We can all think for ourselves, and come up with our own modern methods; no foul in that.
You are basically saying nobody can come up with a better idea for this than you have, or nobody can have a good idea about foundry work unless they have done it for 155 years, and that is just short sighted and misguided.
You are just limiting yourself in my opinion by staying inside someone else's box of thoughts.
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I have edited it to say the following: "Somebody did not do their parting line anything like I would have done it".
No need to personalize it.
I think we are all entitled to our opinions, and I stand by mine, but I am as you say just a little nobody on a hobby forum.
I have never pretended to be a big foundry, so no need to throw that out.
Call off the attack dogs.
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And again, you should not limit yourself to only the methods others have used for 155 years.
We can all think for ourselves, and come up with our own modern methods; no foul in that.
You are basically saying nobody can come up with a better idea for this than you have, or nobody can have a good idea about foundry work unless they have done it for 155 years, and that is just short sighted and misguided.
You are just limiting yourself in my opinion by staying inside someone else's box of thoughts.
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PAT read what I have written. I said "This would have been an ideal candidate for burning out" that part would very much suit a burn out method if cast today. So am more than willing to take on new methods.
You were the one that said that the original foundry men did not know what they were doing.
You were the one that said that the original foundry men did not know what they were doing.
I edited my post to correct that statement.
My apologies; my mistake.
Lets move on.
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My apologies; my mistake.
Lets move on.
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Most do not most gears before 1900 was just sand cast.
Back around 1975 I made pattern for friend for bridge crane power operator. It was about 10" diameter.
Later he decided for advertising to run gear teeth over a milling cutter for better finish.
I lot farm equipment used cast gears into 1970's.
They are very good gear for low speed work
Dave
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I would take that with a pinch of salt.
There is more information at
https://forums.thehomefoundry.org/index.php?threads/lost-pla-using-light-weight-pla.2774/
Please note the homefoundry site is often down.
This has more detail on the process than the one posted here and you can see that all the castings made are poured into the cavity of the LWPLA and so are solid! This is because the pattern is printed only with one wall thickness in 'Vase Mode'.
Hence it is not a valid replacement to lost foam or lost PLA/Wax.
It is not practical for internal details or to be honest any large figurines as these are invariably cast hollow to reduce shrinkage problems and the cost of the material.
I wish I had read that before spending on a spool of LWPLA as I did try a conventional part with low infill and styrofoam sprue. Only the sprue filled! And that was casting in Brass!
Yes, you could print this material as normal even in low density and burn it out but what's the point when regular PLA works fine.
Rich
The Home Foundry (as I heard about it just a few days ago) had some billing glitches, but is back.
I think will always be back even if it disappears for a bit.
These things happen, and you can't always just drop what you are doing and get it instantly resolved.
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I think will always be back even if it disappears for a bit.
These things happen, and you can't always just drop what you are doing and get it instantly resolved.
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LOL, we have cross references going everywhere.
I am going to have to read these various threads; there are a lot of methods being used these days, and things are definitely changing pretty fast.
I have not kept up with much of any method other than sand molds, and so I really have some catching up to do with all the "lost-whatever / investment-whatever" methods that are evolving.
I don't understand all the new methods and materials, so good that we are having these conversations.
Here is a reference posted on THF that is a thread located on this forum:
https://www.homemodelenginemachinist.com/threads/evaporative-pla-casting.35760/
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I am going to have to read these various threads; there are a lot of methods being used these days, and things are definitely changing pretty fast.
I have not kept up with much of any method other than sand molds, and so I really have some catching up to do with all the "lost-whatever / investment-whatever" methods that are evolving.
I don't understand all the new methods and materials, so good that we are having these conversations.
Here is a reference posted on THF that is a thread located on this forum:
https://www.homemodelenginemachinist.com/threads/evaporative-pla-casting.35760/
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Lots of filament choices now.
I have no idea what half of them are.
The filament world is changing fast.
I have heard of wax filament, but I don't recall an example of someone successfully using it.
There is a rather shocking array of different filament types in this catalog.
https://www.esun3d.com/uploads/eSUN-3D-Product-Manual2024.pdf
Does anyone have an index of all the various filament types that are available?
Edit:
Seems like the RC plane folks have been deep-diving into the new filament materials.
https://www.rcgroups.com/forums/showthread.php?3239697-CAD-and-Slicer-design-techniques
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I have no idea what half of them are.
The filament world is changing fast.
I have heard of wax filament, but I don't recall an example of someone successfully using it.
There is a rather shocking array of different filament types in this catalog.
https://www.esun3d.com/uploads/eSUN-3D-Product-Manual2024.pdf
Does anyone have an index of all the various filament types that are available?
Edit:
Seems like the RC plane folks have been deep-diving into the new filament materials.
https://www.rcgroups.com/forums/showthread.php?3239697-CAD-and-Slicer-design-techniques
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We need an index of terms, such as "Evaporative PLA Method", "Lost-PLA Method", "Investment Casting", "Shell Casting", etc., in addition to an index of all the available filament types.
I don't even want to get into the resin-based printers, at least not in this thread.
More terms I ran across:
1. Evaporative pattern casting.
2. Sacrificial pattern process.
3. Lost foam process.
4. Shell process.
5. Investment process.
6. Lost lightweight PLA process.
Some of these terms may refer to the same process.
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I don't even want to get into the resin-based printers, at least not in this thread.
More terms I ran across:
1. Evaporative pattern casting.
2. Sacrificial pattern process.
3. Lost foam process.
4. Shell process.
5. Investment process.
6. Lost lightweight PLA process.
Some of these terms may refer to the same process.
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I am with Rich on this one, ie: I want to see several successful examples before I try a new product or method.
I saw a video a few years ago about using wax filament to 3D print patterns, and it was suppose to be a really big thing.
The I read where they could not get the new waxed filament problems worked out.
So I am open to any new idea that gives consistent and structurally sound results, but I do have a lot of sand, binder, and PLA element, so there is that.
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Here is an example of a shell molding process using resin-bound sand.
I knew Stuart used a shell molding process with the mold material pressed into hot mold-halves, but I have never seen this applied to resin sand, and was not aware that it could be done.
I generally block out the interior of my resin-sand flasks to save as much sand as possible, since resin-bound sand is not easily reusable.
The key would be getting a complete fill of the shell, and I am not sure exactly how they are injecting the sand into the shell molds.
Lots of interesting new methods out there.
I am not sure if I could use this effectively or not.
Probably more suitable for mass production.
I have seen a thin resin-bound mold surrounded by traditional greensand in a flask, but I don't recall where I saw that.
Looks like these shells are surrounded by dry sand.
Using core adhesive in strategic places as shown at 3:40 in the video is one key to avoiding flash and runouts.
Resin-bound sand is very strong by itself once it fully cures (in about 45 minutes), and I have not had problems with these type molds failing during a pour even when some of the sections are as thin as 1/2".
I did have some mold halves separate when I did not weight the top of the mold.
You can always use a slip-over sheet metal jacket around a bound sand mold, and stack a large amount of weights on top to prevent mold float.
You can stack a lot of weigh on top of an unsupported resin-bound mold without problems.
I use one of the Ask Chemical products to adhere resin-bound molds together.
I forget the exact name of it, but it is a single part adhesive, and is applied as you would typically apply glue from a bottle.
Apparently you can hot glue bound molds together also, as shown in this video.
You would have to be sure the hot glue does not flash/gas when the hot iron hits it.
I knew Stuart used a shell molding process with the mold material pressed into hot mold-halves, but I have never seen this applied to resin sand, and was not aware that it could be done.
I generally block out the interior of my resin-sand flasks to save as much sand as possible, since resin-bound sand is not easily reusable.
The key would be getting a complete fill of the shell, and I am not sure exactly how they are injecting the sand into the shell molds.
Lots of interesting new methods out there.
I am not sure if I could use this effectively or not.
Probably more suitable for mass production.
I have seen a thin resin-bound mold surrounded by traditional greensand in a flask, but I don't recall where I saw that.
Looks like these shells are surrounded by dry sand.
Using core adhesive in strategic places as shown at 3:40 in the video is one key to avoiding flash and runouts.
Resin-bound sand is very strong by itself once it fully cures (in about 45 minutes), and I have not had problems with these type molds failing during a pour even when some of the sections are as thin as 1/2".
I did have some mold halves separate when I did not weight the top of the mold.
You can always use a slip-over sheet metal jacket around a bound sand mold, and stack a large amount of weights on top to prevent mold float.
You can stack a lot of weigh on top of an unsupported resin-bound mold without problems.
I use one of the Ask Chemical products to adhere resin-bound molds together.
I forget the exact name of it, but it is a single part adhesive, and is applied as you would typically apply glue from a bottle.
Apparently you can hot glue bound molds together also, as shown in this video.
You would have to be sure the hot glue does not flash/gas when the hot iron hits it.
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Here is an example of a sodium silicate only mold.
What many people seem to overlook is that with bound sand molds, the molds can be very thin.
There is no need for 4" tall cope and 4" tall drag flask halves with bound sand.
He could possibly get away with a 1.5" tall cope, and a 1.5" tall drag.
What many people seem to overlook is that with bound sand molds, the molds can be very thin.
There is no need for 4" tall cope and 4" tall drag flask halves with bound sand.
He could possibly get away with a 1.5" tall cope, and a 1.5" tall drag.
